Tantalum (Ta) is a material widely used throughout various industrial sectors, such as in the aerospace industry and in the defense sector, as well as in the electrical, electronic, mechanical, and chemical fields, due to desirable mechanical and physical properties such as a high melting point, excellent flexibility, excellent corrosion resistance, and the like.
Since tantalum can form a stable anodic oxide film, tantalum has been widely used as a material for positive electrodes of small capacitors. In accordance with the rapid development of information technology (IT), information and communications technology (ICT) and electronics technology, the use of tantalum has been increasing every year.
Generally, a capacitor is a condenser temporarily storing electricity therein, and includes two flat plate electrodes. Two flat plate electrodes are disposed in close proximity to each other, and insulated from each other when a dielectric substance is inserted therebetween. The two plate electrodes may be charged with electrical charges due to attractive force, thereby allowing electricity to be accumulated therein. Such a capacitor stores electrical charges and electrical fields in a space enclosed by two conductors, and is commonly used to acquire capacitance.
A tantalum capacitor containing a tantalum material has a structure in which voids are formed when tantalum powder is sintered and hardened.
For example, the tantalum capacitor may be completed by forming tantalum oxide (Ta2O5) on a hardened tantalum surface using an anodic oxidation method, forming a manganese dioxide (MnO2) layer, an electrolyte, on the tantalum oxide acting as a dielectric substance, forming a carbon layer and a metal layer on the manganese dioxide layer to form a body, forming an anode terminal and a cathode terminal on the body to be connected thereto for mounting thereof on a printed circuit board (PCB), and forming a sealing part.
There is no direct current (DC)-bias direction in the tantalum capacitor, and the tantalum capacitor has no affect in regard to acoustic noise. In the tantalum capacitor, equivalent series inductance (ESL) is defined as parasitic inductance on a circuit, and it is significantly important when designing a power supply unit, or the like, to decrease equivalent series inductance of the tantalum capacitor.
Recently, however, with the introduction of premium electronic products such as smartphones, demand for a capacitor capable of being driven at a high frequency has increased, but a general tantalum capacitor does not satisfy this demand.